• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.130-130
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• 2002

Purpose： To evaluate the liver enhancement pattern of MR images obtained after administration of manganese phthalocyanine (MnPC), which is a newly developed macromolecular MR contrast agent, In experimentally implanted VX2 tumor of rabbits and compare with G4-DTPA and Mn-DPDP.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.108-108
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• 2001

Purpose： To correlate the histological differentiation of hepatocellular carcinomas (HCCs) with finding on triple contrast-enhanced MR imaging using gadolinium-chelates, superparamganetic ire oxides (SPIO), and mangafodipir trisodium. Method： Ten patients with proven HCC underwent triple contrast-enhanced MRI befo surgical resection. Subjective ratings of the enhancement pattern and degree were compare with the histological grades determined on surgical specimen. Quantitative measurements signal-to-noise ratio (S/N) of the lesion and the lesion-to-liver contrast-to-noise ratio C/N on the enhanced MR images, and the degree of S/N and C/N changes between the unenhanced and enhanced images were also correlated with the histological grades.

• Investigative Magnetic Resonance Imaging
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• v.21 no.3
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• pp.148-153
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• 2017

Purpose: To identify the differences between injected cement volumes during vertebroplasty procedures according to the enhancement pattern of pre-procedure magnetic resonance imaging (MRI) findings. Materials and Methods: Thirty-two patients who underwent 52 vertebroplasty procedures as well as pre-procedure contrast-enhanced spine MRI in the authors' institution were reviewed retrospectively. The 52 procedures were divided into two groups according to different enhancement patterns shown by pre-procedure MR imaging [E(+) and E(-)]. The volumes of the enhancing/non-enhancing portions of the fractured vertebral body shown by pre-procedural MR imaging were calculated and compared to the volumes of the injected cement during the vertebroplasty procedures. Results: The 52 injections included 28 (56%) in Group E(+) and 24 (44%) in Group E(-). The actual volume ratio of the injected cement to the volume of the non-enhanced or enhanced region calculated based on the contrast-enhanced MRI was $0.22{\pm}0.11(cc/cm^3)$ in the E(+) group and $0.93{\pm}0.62(cc/cm^3)$ in the E(-) group. The average amount of injected cement was significantly different between Group E(+) and Group E(-) (P < 0.001). In addition, the ratio of the injected cement amount to the volume of the enhanced or non-enhanced portion based on the contrast-enhanced MRI in Group E(-) was significantly higher than that of Group E(+) (P < 0.001). Conclusion: Different enhancement patterns shown by pre-procedure MRI can predictors of the injected cement volume during vertebroplasty procedures for osteoporotic fractures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.544-564
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• 2022

Underwater images often suffer from color distortion, blurring and low contrast, which is caused by the propagation of light in the underwater environment being affected by the two processes: absorption and scattering. To cope with the poor quality of underwater images, this paper proposes a multiscale fusion underwater image enhancement method based on channel attention mechanism and local binary pattern (LBP). The network consists of three modules: feature aggregation, image reconstruction and LBP enhancement. The feature aggregation module aggregates feature information at different scales of the image, and the image reconstruction module restores the output features to high-quality underwater images. The network also introduces channel attention mechanism to make the network pay more attention to the channels containing important information. The detail information is protected by real-time superposition with feature information. Experimental results demonstrate that the method in this paper produces results with correct colors and complete details, and outperforms existing methods in quantitative metrics.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.493-497
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• 2012

This study was conducted to retrospectively evaluate the pattern of contrast enhancement with SonoVue on gray-scale ultrasonography of hepatic angiomyolipoma (HAML). Imaging features of 33 pathologically proven HAML lesions in 33 patients who underwent baseline ultrasound and contrast-enhanced ultrasonography (CEUS) were assessed retrospectively. All lesions were enhanced in the arterial phase and showed whole-tumor filling in. Thirty-two of 33 (97%) lesions showed early positive enhancement in the arterial phase. Twenty-three of these exhibited isoechoic or hyperechoic features in the portal phase. HAML demonstrate characteristic manifestations with SonoVue-enhanced real-time gray-scale ultrasonography.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.28-35
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• 2010

A new electrode structure in a plasma display panel was designed in a way to increase the bright room contrast ratio (BRCR). The area of the black matrix pattern to get a low reflection from the panel surface was enlarged using the new electrode design concept. The electrical characteristics such as firing voltage, voltage margin and power consumption were measured. The luminance of the panel was measured and the luminous efficiency was calculated. It was found that the new electrode structure was very effective to enhance the BRCR.

• Investigative Magnetic Resonance Imaging
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• v.19 no.3
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• pp.191-195
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• 2015

We present a 53-year-old woman with a large chest wall mass in the interpectoral space, which was eventually confirmed as a lipogranuloma resulting from hydrogel implant rupture. Ultrasonography (US) showed reduced implant volume with surrounding peri-implant fluid collection, suggesting the possibility of implant rupture. A heterogeneously hypoechoic mass was found between the pectoralis major and minor muscles adjacent to the ruptured implant. On magnetic resonance imaging (MRI), there was a large mass in the left interpectoral space of the upper inner chest wall. The mass showed slightly high signal intensity (SI) on pre-contrast T1-weighted image (WI) with mixed iso and high SI on T2-WI. The signal of the mass was suppressed using the water suppression technique but not with the fat suppression technique on T2-WI. The mass showed diffuse enhancement upon contrast enhancement. The enhancing kinetics showed persistent enhancement pattern. US-guided core needle biopsy revealed a lipogranuloma and removal confirmed a ruptured PIP hydrogel implant.

• The Korean Journal of Pain
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• v.22 no.1
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• pp.52-57
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• 2009

Background: Transforaminal epidural injection (TEI) may be useful to treat unilateral pain that has a dermatomal distribution. In this approach, the needle tip can be placed closer to the dorsal root ganglion and ventral aspect of the nerve root. However many studies have reported that serious complications following TEI occurred more frequently when it was conducted at the cervical level. One of the presumptive mechanisms of the complication is intravascular injection. Therefore this study was conducted to identify the incidence of complications in response to intravascular injections at cervical segments. Methods: This study included all patients, who visited our pain clinic and had radicular symptoms or herpes zoster associated pain. All procedures were conducted under fluoroscopic guidance with contrast enhancement by one of the authors. After the ideal needle position was confirmed by biplanar fluoroscopy, the blood aspiration through the needle hub was evaluated, and a 3 ml mixture of nonionic contrast (2 ml) with normal saline (1 ml) was injected at a rate of 0.3-0.5 ml/sec continuously under real time fluoroscopic visualization. We then classified the contrast spreading pattern as neural, simultaneous neural and vascular, or vascular. Results: A total 71 cervical TEIs were performed. In 26 cases (36.6%), the contrast only spread to the nerve sheath. However, 45 cases (63.4%) showed an intravascular spreading pattern, 37 (52.1%) of which showed a neural and vascular pattern and 8 (11.3%) of which showed only a vascular pattern. Conclusions: Approximately two thirds of the cases of cervical TEI were found to lead to intravascular spreading, which is much higher than the incidence reported in previous studies.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.7
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• pp.297-300
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• 2015

In medical ultrasonography, transit time and contrast enhancement patterns are considered as important parameters to analyze liver diseases. In many recent researches, time-intensity curves(TIC) have been used for calculating the transit time of the contrast agents. However, the intensity curve may include the variations which are caused by the micro-bubble effect of contrast agents. In this paper, we propose a complementary approach to diagnostic parameter extraction which utilizes a density information as well as the intensity data. The proposed technique improves the accuracy in extraction of the transit time and velocity of contrast agents for detection and characterization of focal liver lesions. Through the experiments using a set of clinical data, we show that the proposed methods can improve the reliability of the parametric image data.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.306-315
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• 1998

MR findings in nine patients(three female, six male) with neuro-Behcet's disease were retrospectively analyzed. NeuroBehcet's disease was diagnosed on the basis of typical clinical symptoms. Involved site, pattern, signal intensity, and contrast enhancement pattern on MRI were evaluated. In addition, follow up MR imaging was performed in four patients. The midbrain(7/9), internal capsule(7/9), pons(6/9), thalamus(6/9), basal ganglia (5/9), middle cerebella peduncle(4/9), medulla oblongata(2/9), and subcortical white matter(2/9) are involved on MRI. The size of lesions was 1cm to 3cm and their margin was ill-defined and patchy. Inhomogeneous high signal intensity on the T2-weighted images and low signal intensity on T1-weighted images was seen respectively. In four of nine cases, there was focal enhancement. On follow up MR imaging, improvement or recurrance of the lesions was found. Also in two cases of follow up cases, there was artophy in brainstem and(or) middle cerebellar peduncles. In conclusion, MR imaging with systemic clinical symptoms is useful for diagnosing neuro-Behcet's disease.